This application relates generally to systems, methods, and apparatuses for digital signal detection, and more particularly to a non-linear Viterbi detector with reduced complexity.
With the continuing demand for high-speed digital communications systems and high-density digital storage systems, various techniques have been applied to increase the capacity of these systems. For example, in magnetic media storage, many manufacturers are using perpendicular recording rather than traditional longitudinal recording to pack more information into a smaller area. However, as data speeds and storage densities are pushed to their limits and beyond, the amount of signal distortion on information-carrying signals have increased dramatically. Thus, detectors are heavily relied upon to interpret the information in these highly distorted signals.
In fact, digital transmission and storage systems have reached a point where signal-dependent noise, such as transition jitter, often overwhelm white noise. Therefore, non-linear Viterbi detectors, designed to whiten signal-dependent noise, are currently being used in place of their less-effective linear counterpart. However, current non-linear Viterbi detectors are highly complex and typically consume a large amount of resources. In particular, because such detectors typically run at high speeds, they often have large area and high power consumption. Thus, non-linear Viterbi detectors might not be appropriate in various detection situations, such as in iterative decoding systems, where multiple detectors are cascaded. Therefore, it would be desirable to provide techniques for reducing the complexity of non-linear Viterbi detectors for high-speed communications systems and high-density storage systems.